Luminescent Properties of Natural Substances in Solutions under Low-Dose Radiation Exposure

Abstract

Humic substances or natural organic materials recently have they attracted steady attention as promising biologically active substances. These compounds are widely distributed in natural waters and soils, and have a wide range of chemical and physical properties. Their structure includes a large number of diverse functional groups, which determines their complex-forming, surface-active and redox properties, as well as contributes to their biological activity and possess detoxifying properties. Using humic substances, it is possible to reduce the toxicity of an important class of toxicants - radionuclides. Technogenic pollution by radioactive elements is a consequence of the extraction and processing of radioactive materials, the operation of nuclear power stations, the placement of radioactive waste, accidents at nuclear enterprises, etc. In most cases, technogenic radioactive contamination is caused by isotopes of uranium, thorium, etc., as well as tritium, which is one of the most common decay products of radioisotopes used in the nuclear industry. As a rule, enterprises control discharges, conduct wastewater treatment, reducing the content of radionuclides to an acceptable limit. Moreover, even residual radioactivity can lead to disruption of the physiological functions of aquatic microorganisms, which are the initial link in the food chain for all organisms. The influence of biologically active nanostructures is able to correct the state of aquatic microorganisms. In the presence of humic substances under the influence of radiation, organic molecules are transformed by the mechanisms of direct and indirect photolysis. However, experiments show that the addition of a humic fraction containing both humic and fulvic acids to an aqueous solution of phenol leads to a decrease in the efficiency of phenol decomposition. We managed to find the conditions and fix the effective decomposition of phenol in an aqueous solution when exposed to radiation with a wavelength of 222 nm from an excilamp in the presence of fulvic acid.